|By Ian Ransom

MELBOURNE (Reuters) - Novak Djokovic has dominated the blue courts of Melbourne Park for the best part of a decade but the defending champion still fears over-confidence could prove his undoing at the Australian Open.

Set to bid for a record seventh title and a second hat-trick of trophies after his 2011-13 run, the Serb has often seemed invincible in Australia.

This time, however, he has arrived Down Under in a more humble position, without the top seed for the first time in three years after conceding the number one ranking to Briton Andy Murray.

"I never had an invincibility, although I thank you for the compliment," he told reporters at Melbourne Park on Saturday, two days before the first grand slam of the season starts.

"Nobody is invincible. I never thought of myself as a superior player on the court, even though of course at times I

was very confident, I was winning a lot of matches.

"But, you know, knowing how it feels on the court, if you get overconfident, that's why I don't want to get into that kind of state of mind.

"I still want to put myself in a position where I'm quite even to other players, fight for this trophy as anybody else, even though I'm defending champion."

After completing a sweep of the grand slam titles at last year's French Open, Djokovic suffered a form slump and Murray poached his number one ranking at the World Tour finals, but winning back the top spot was not the Serb's "main priority".

"As a consequence of the results, if I become number one, that's great. Of course, that's what I want," he added.

"I really would like to take one tournament at a time and try to win as many matches as possible. Then, as I said, as a consequence to that, if I become number one, I'll be thrilled."

While hardly putting him back in the pack, 29-year-old Djokovic's second seeding has resulted in a tougher draw than in years past.

He faces a stern opening test against Spanish veteran Fernando Verdasco, who dumped Rafa Nadal out of the first round last year and held five match points over the Serb at the Qatar Open.

A possible fourth round match against Bulgarian talent Grigor Dimitrov, in red-hot form after upsetting Kei Nishikori and Milos Raonic to win the Brisbane International, follows.

But Djokovic has also enjoyed sound preparation and landed a psychological blow against Murray by beating him in the final at Qatar last week to snap the Scot's 28-match winning streak.

"I couldn't ask for a better start of the season," Djokovic said. "I still haven't had any nightmares, so I can't call it a nightmare draw. I just see it as a huge challenge. I hope I'll be able to deliver."